[DevTools] Remove WebDevToolsAgent::setLayerTreeId calls.

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/gpu/render_widget_compositor.h"
 
 #include <limits>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 510 matching lines @@
   return scoped_ptr<cc::SwapPromiseMonitor>(
       new cc::LatencyInfoSwapPromiseMonitor(
           latency, layer_tree_host_.get(), NULL));
 }
 
 void RenderWidgetCompositor::QueueSwapPromise(
     scoped_ptr<cc::SwapPromise> swap_promise) {
   layer_tree_host_->QueueSwapPromise(swap_promise.Pass());
 }
 
-int RenderWidgetCompositor::GetLayerTreeId() const {
-  return layer_tree_host_->id();
-}
-
 int RenderWidgetCompositor::GetSourceFrameNumber() const {
   return layer_tree_host_->source_frame_number();
 }
 
 void RenderWidgetCompositor::SetNeedsUpdateLayers() {
   layer_tree_host_->SetNeedsUpdateLayers();
 }
 
 void RenderWidgetCompositor::SetNeedsCommit() {
   layer_tree_host_->SetNeedsCommit();
@@ skipping 391 matching lines @@
   cc::ContextProvider* provider =
       compositor_deps_->GetSharedMainThreadContextProvider();
   // provider can be NULL after the GPU process crashed enough times and we
   // don't want to restart it any more (falling back to software).
   if (!provider)
     return;
   provider->ContextGL()->RateLimitOffscreenContextCHROMIUM();
 }
 
 }  // namespace content